service data advertisement and 128 uuid

Question

Hi, 
 I searched through the devzone but I cannot find a answer on this question but the question has been asked before.
Some background. I have a working solution from another vendor and I want to switch to Nordic. In this solution I use service data to advertise our product including some data about the product. I am now looking in the SDK to see how I can implement this with Nordic.
Ok, so the ble_advdata_service_data_t structure needs a uint16_t for de uuid. I use 128 bits uuid's. I can add them with sd_ble_uuid_vs_add. This returns a UUID type. Now the question is. How do I match the UUID type return from sd_ble_uuid_vs_add to the service_uuid field in ble_advdata_service_data_t structure. 
 Cheers, Marcel

FormerMember · Accepted Answer

In order to add "Service data" with 128 bit UUID to the advertising data, a few modifications to the code in the SDK has to be made. Below are the modifications I did. I used SDK 7.1.0, and tested with ble_app_hrs. Note 1: This is not a general solution, it just shows how "service data" with a 128 bit UUID can be added. Note 2: remember that 31 bytes is the maximum payload in an advertising packet. ble_advdata.h: ble_advdata_service_data_t has to be modified to handle 128 bit UUID: /**@brief Service data structure. */ typedef struct { ble_uuid128_t service_uuid; /**< Service UUID. */ uint8_array_t data; /**< Additional service data. */ } ble_advdata_service_data_t; app_util.h: An encoding function for a 128 bit UUID has to be added: /**@brief Function for encoding a 128 bit UUID value. * * @param[in] value Value to be encoded. * @param[out] p_encoded_data Buffer where the encoded data is to be written. * * @return Number of bytes written. */ static __INLINE uint8_t uint128_encode(ble_uuid128_t value, uint8_t * p_encoded_data) { p_encoded_data[0] = (uint8_t) value.uuid128[0]; p_encoded_data[1] = (uint8_t) value.uuid128[1]; p_encoded_data[2] = (uint8_t) value.uuid128[2]; p_encoded_data[3] = (uint8_t) value.uuid128[3]; p_encoded_data[4] = (uint8_t) value.uuid128[4]; p_encoded_data[5] = (uint8_t) value.uuid128[5]; p_encoded_data[6] = (uint8_t) value.uuid128[6]; p_encoded_data[7] = (uint8_t) value.uuid128[7]; p_encoded_data[8] = (uint8_t) value.uuid128[8]; p_encoded_data[9] = (uint8_t) value.uuid128[9]; p_encoded_data[10] = (uint8_t) value.uuid128[10]; p_encoded_data[11] = (uint8_t) value.uuid128[11]; p_encoded_data[12] = (uint8_t) value.uuid128[12]; p_encoded_data[13] = (uint8_t) value.uuid128[13]; p_encoded_data[14] = (uint8_t) value.uuid128[14]; p_encoded_data[15] = (uint8_t) value.uuid128[15]; return 16; } ble_advdata.c: The service_data_encode(..) function has to be modified to encode the 128 bit UUID. static uint32_t service_data_encode(const ble_advdata_t * p_advdata, uint8_t * p_encoded_data, uint8_t * p_len) { uint8_t i; // Check parameter consistency. if (p_advdata->p_service_data_array == NULL) { return NRF_ERROR_INVALID_PARAM; } for (i = 0; i < p_advdata->service_data_count; i++) { ble_advdata_service_data_t * p_service_data; uint8_t data_size; p_service_data = &p_advdata->p_service_data_array[i]; data_size = 16 + p_service_data->data.size; // sizeof(uint16_le_t) + p_service_data->data.size; // Encode Length and AD Type. p_encoded_data[(*p_len)++] = 1 + data_size; p_encoded_data[(*p_len)++] = BLE_GAP_AD_TYPE_SERVICE_DATA_128BIT_UUID; //BLE_GAP_AD_TYPE_SERVICE_DATA; // Encode service UUID. //(*p_len) += uint16_encode(p_service_data->service_uuid, &p_encoded_data[*p_len]); (*p_len) += uint128_encode(p_service_data->service_uuid, &p_encoded_data[*p_len]); // added for encoding of 128 bit uuid. // Encode additional service data. if (p_service_data->data.size > 0) { if (p_service_data->data.p_data == NULL) { return NRF_ERROR_INVALID_PARAM; } memcpy(&p_encoded_data[*p_len], p_service_data->data.p_data, p_service_data->data.size); (*p_len) += p_service_data->data.size; } } return NRF_SUCCESS; } main.c : I made the device name short and added "service data" in advertising_init(..): In order to make sure that the advertising data didn't exceed 31 bytes, I change the device name to something short: #define DEVICE_NAME "H" I changed advertising_init(..) to the following: /**@brief Function for initializing the Advertising functionality. * * @details Encodes the required advertising data and passes it to the stack. * Also builds a structure to be passed to the stack when starting advertising. */ static void advertising_init(void) { uint32_t err_code; ble_advdata_t advdata; uint8_t flags = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE; uint8_t service_data[3] = {1,2,3}; uint8_t service_data_len = sizeof(service_data)/sizeof(service_data[0]); ble_uuid128_t service128bit_uuid = {{0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF, 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99}}; ble_advdata_service_data_t service_data_struct; ble_uuid_t adv_uuids[] = { {BLE_UUID_HEART_RATE_SERVICE, BLE_UUID_TYPE_BLE}, {BLE_UUID_BATTERY_SERVICE, BLE_UUID_TYPE_BLE}, {BLE_UUID_DEVICE_INFORMATION_SERVICE, BLE_UUID_TYPE_BLE} }; // Build and set advertising data. memset(&advdata, 0, sizeof(advdata)); advdata.name_type = BLE_ADVDATA_FULL_NAME; advdata.include_appearance = true; advdata.flags.size = sizeof(flags); advdata.flags.p_data = &flags; //advdata.uuids_complete.uuid_cnt = sizeof(adv_uuids) / sizeof(adv_uuids[0]); //advdata.uuids_complete.p_uuids = adv_uuids; advdata.p_service_data_array = &service_data_struct; advdata.p_service_data_array->service_uuid = service128bit_uuid; advdata.p_service_data_array->data.p_data = service_data; advdata.p_service_data_array->data.size = service_data_len; advdata.service_data_count = 1; err_code = ble_advdata_set(&advdata, NULL); APP_ERROR_CHECK(err_code); // Initialize advertising parameters (used when starting advertising). memset(&m_adv_params, 0, sizeof(m_adv_params)); m_adv_params.type = BLE_GAP_ADV_TYPE_ADV_IND; m_adv_params.p_peer_addr = NULL; // Undirected advertisement. m_adv_params.fp = BLE_GAP_ADV_FP_ANY; m_adv_params.interval = APP_ADV_INTERVAL; m_adv_params.timeout = APP_ADV_TIMEOUT_IN_SECONDS; }

service data advertisement and 128 uuid

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